I don't think that the phrase "sovereign states don't have rights" is even controversial at all. I also think think that any adult that has gone through any decent education will probably be familiar with the phrase or concept, even if they can't ELI5 it, the same way we are familiar with or have heard of other related concepts like democracy, separation of powers, habeas corpus, human rights, individual rights, sovereignty, etc. In fact, sovereignty is perhaps where the debate should live because sovereignty is, after all, the right of a "state" over itself, which seems to contradict the idea that sovereign states have no rights (it doesn't). Anyway, enough of that.
My first comment was short because it was simply intended as a nudge or reminder that hey, before we go down the road of overthinking why the USA has a right to hold some secrets, let's just remember that the idea itself is difficult to defend, especially in a democracy.